Search results for "interpretation"

Violation of Siegert's theorem in the electro-excitation of the (1−, T = 0)-level at 7.117 MeV in 16O

1989

Abstract Cross sections are measured for the electro-excitation of the first 1−-level in 16O at extremely small momentum transfer. The model-independent interpretation with a Fourier-Bessel expansion of the transition charge density reveals an incompatibility with the life-time measurement at the photon point, i.e. a violation of Siegert's theorem.

Linear Nuclei: A Density Functional Interpretation

1997

We show that linear shape isomers of small even-even nuclei exist with nearly any internucleon interactions. The shapes of the linear isomers look like chains of alpha-particles, but single-particle spectrum reveals that alpha-particle interpretation is not needed. Indeed, the same shapes are obtained even with noninteracting particles in a rectangular cavity. Linear shape isomers are shown to exist also in metal clusters.

Novel Interpretation of the “Θ+(1540)Pentaquark” Peak

2010

This work is partly supported by the DGICYT contract FIS2006-03438, the Generalitat Valenciana in the program Prometeo and the EU Integrated Infrastructure Initiative Hadron Physics Project, n.227431. A. M. T thanks the support from a FPU grant of the MICINN.

A decade of SN 1993J : discovery of radio wavelength effects in the expansion rate

2009

We studied the growth of the shell-like radio structure of supernova SN 1993J in M 81 from September 1993 to October 2003 with very-long-baseline interferometry (VLBI) observations at the wavelengths of 3.6, 6, and 18 cm. We developed a method to accurately determine the outer radius (R) of any circularly symmetric compact radio structure such as SN 1993J. The source structure of SN 1993J remains circularly symmetric (with deviations from circularity under 2%) over almost 4000 days. We characterize the decelerated expansion of SN 1993J until approximately day 1500 after explosion with an expansion parameter m = 0.845 ± 0.005 (R ∝ tm). However, from that day onwards the expansion differs whe…

Fundamental Principles of Quantum Mechanics

2001

There are two alternative methods of quantizing a system: a) quantization via the Feynman Path Integral (equivalent to Schwinger’s Action Principle); b) canonical quantization.

Probe Coherence Volume and the Interpretation of Scattering Experiments

1998

Comparative investigation of the freezing phenomena for quantum correlations under nondissipative decoherence

2013

We show that the phenomenon of frozen discord, exhibited by specific classes of two-qubit states under local nondissipative decoherent evolutions, is a common feature of all known bona fide measures of general quantum correlations. All those measures, despite inducing typically inequivalent orderings on the set of nonclassically correlated states, return a constant value in the considered settings. Every communication protocol which relies on quantum correlations as resource will run with a performance completely unaffected by noise in the specified dynamical conditions. We provide a geometric interpretation of this

Quantum walks and non-Abelian discrete gauge theory

2016

A new family of discrete-time quantum walks (DTQWs) on the line with an exact discrete $U(N)$ gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac fermion coupled to usual $U(N)$ gauge fields in $2D$ spacetime. A discrete generalization of the usual $U(N)$ curvature is also constructed. An alternate interpretation of these results in terms of superimposed $U(1)$ Maxwell fields and $SU(N)$ gauge fields is discussed in the Appendix. Numerical simulations are also presented, which explore the convergence of the DTQWs towards their continuous limit and which also compare the DTQWs with classical (i.e. non-qu…

Pentaquark and diquark–diquark clustering: a QCD sum rule approach

2004

In this work we study the Theta(1540) in the framework of QCD sum rules based on (ud)^2\bar{s} diquark clustering as suggested by Jaffe and Wilczek. Within errors, the mass of the pentaquark is compatible with the experimentally measured value. The mass difference between the Theta and the pentaquark with the quantum numbers of the nucleon amounts to 70 MeV, consistent with the interpretation of the N(1440) as a pentaquark.

Simulation of skin reflectance images using 3D tissue modeling and multispectral Monte Carlo light propagation.

2008

In this work we propose a method to simulate the expected, i.e. seen by a camera, multispectral reflectance images of a large skin surface area by combining Monte Carlo light propagation model and realistic tissue modeling based on three dimensional data acquisition of human body areas. In particular, we aim to simulate more accurately light transport in biological tissue by taking into account the geometrical topography of the skin surface, the structure and optical properties of the skin layers, and the subcutaneous veins in presence. We describe our computation method in detail and present simulated reflectance images results.